Add option --experimental_discard_actions_after_execution in order to turn it off after a release.
Discarding actions hasn't been shown to have a significant positive effect on heap memory usage, after careful research by mschaller@. It's holding back other projects (threading Fileset metadata through) and adding complexity, so it's time to kill it. Out of an abundance of caution, I'll keep actions in memory via a flag flip, then, if it sticks, I'll change the default, and then I'll unwire everything.
PiperOrigin-RevId: 196682768
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
index 42cbc43..cd4e86d 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
@@ -403,6 +403,18 @@
)
public boolean keepStateAfterBuild;
+ @Option(
+ name = "discard_actions_after_execution",
+ defaultValue = "true",
+ documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
+ metadataTags = OptionMetadataTag.INCOMPATIBLE_CHANGE,
+ effectTags = {OptionEffectTag.LOSES_INCREMENTAL_STATE},
+ help =
+ "If true, Blaze will clear actions from memory after it executes them. Has no effect "
+ + "unless --notrack_incremental_state is also specified. Do not use unless instructed"
+ + " by the Blaze team.")
+ public boolean discardActionsAfterExecution;
+
/** Converter for jobs: [0, MAX_JOBS] or "auto". */
public static class JobsConverter extends RangeConverter {
/**
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
index e63ae09..aaeed3f 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
@@ -612,12 +612,15 @@
}
}
+ removeActionsAfterEvaluation.set(
+ !trackIncrementalState
+ && requestOptions != null
+ && requestOptions.discardActionsAfterExecution);
// Now check if it is necessary to wipe the previous state. We do this if either the previous
// or current incrementalStateRetentionStrategy requires the build to have been isolated.
if (oldValueOfTrackIncrementalState != trackIncrementalState) {
logger.info("Set incremental state to " + trackIncrementalState);
evaluatorNeedsReset = true;
- removeActionsAfterEvaluation.set(!trackIncrementalState);
} else if (!trackIncrementalState) {
evaluatorNeedsReset = true;
}
diff --git a/src/test/shell/integration/discard_graph_edges_test.sh b/src/test/shell/integration/discard_graph_edges_test.sh
index d2da4cf..9a69c4e 100755
--- a/src/test/shell/integration/discard_graph_edges_test.sh
+++ b/src/test/shell/integration/discard_graph_edges_test.sh
@@ -371,6 +371,39 @@
BUILD_FLAGS="$old_build_flags"
}
+function test_actions_deleted_after_execution_explicit() {
+ readonly local old_build_flags="$BUILD_FLAGS"
+ BUILD_FLAGS="$BUILD_FLAGS --discard_actions_after_execution"
+ test_actions_deleted_after_execution
+ BUILD_FLAGS="$old_build_flags"
+}
+
+function test_actions_not_deleted_after_execution() {
+ mkdir -p foo || fail "Couldn't mkdir"
+ cat > foo/BUILD <<'EOF' || fail "Couldn't write file"
+genrule(name = "foo", cmd = "touch $@", outs = ["foo.out"])
+EOF
+ bazel build $BUILD_FLAGS //foo:foo >& "$TEST_log" || fail "Expected success"
+ "${bazel_javabase}/bin/jmap" -histo:live "$(bazel info server_pid)" > histo.txt
+ local genrule_action_count="$(extract_histogram_count histo.txt \
+ 'GenRuleAction$')"
+ if [[ "$genrule_action_count" -gt 0 ]]; then
+ cat histo.txt >> "$TEST_log"
+ fail "GenRuleAction unexpectedly found: $genrule_action_count"
+ fi
+
+ bazel build $BUILD_FLAGS --nodiscard_actions_after_execution //foo:foo \
+ >& "$TEST_log" || fail "Expected success"
+ "${bazel_javabase}/bin/jmap" -histo:live "$(bazel info server_pid)" > histo.txt
+ genrule_action_count="$(extract_histogram_count histo.txt \
+ 'GenRuleAction$')"
+ if [[ "$genrule_action_count" -lt 1 ]]; then
+ cat histo.txt >> "$TEST_log"
+ fail "GenRuleAction unexpectedly not found: $genrule_action_count"
+ fi
+
+}
+
function test_dump_after_discard_incrementality_data() {
bazel build --notrack_incremental_state //testing:mytest >& "$TEST_log" \
|| fail "Expected success"
